[v4,1/5] clk: sunxi: Add CLK_OF_DECLARE support for sun8i-a23-apb0-clk driver

Commit Message

Chen-Yu Tsai Nov. 29, 2015, 3:03 a.m. UTC

The APBS clock on sun9i is the same as the APB0 clock on sun8i. With
sun9i we are supporting the PRCM clocks by using CLK_OF_DECLARE,
instead of through a PRCM mfd device and subdevices for each clock
and reset control. As such we need a CLK_OF_DECLARE version of
the sun8i-a23-apb0-clk driver.

Also, build it for sun9i/A80, and not just for configurations with
MFD_SUN6I_PRCM enabled.

Signed-off-by: Chen-Yu Tsai <[e-mail]>
---
 drivers/clk/sunxi/Makefile         |  5 +--
 drivers/clk/sunxi/clk-sun8i-apb0.c | 71 +++++++++++++++++++++++++++++++-------
 2 files changed, 62 insertions(+), 14 deletions(-)

Comments

Maxime Ripard Dec. 1, 2015, 10:04 a.m. UTC | #1

Hi,

On Sun, Nov 29, 2015 at 11:03:06AM +0800, Chen-Yu Tsai wrote:
> The APBS clock on sun9i is the same as the APB0 clock on sun8i. With
> sun9i we are supporting the PRCM clocks by using CLK_OF_DECLARE,
> instead of through a PRCM mfd device and subdevices for each clock
> and reset control. As such we need a CLK_OF_DECLARE version of
> the sun8i-a23-apb0-clk driver.
> 
> Also, build it for sun9i/A80, and not just for configurations with
> MFD_SUN6I_PRCM enabled.
> 
> Signed-off-by: Chen-Yu Tsai <[e-mail]>
> ---
>  drivers/clk/sunxi/Makefile         |  5 +--
>  drivers/clk/sunxi/clk-sun8i-apb0.c | 71 +++++++++++++++++++++++++++++++-------
>  2 files changed, 62 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> index cb4c299214ce..c55d5cd1c0e5 100644
> --- a/drivers/clk/sunxi/Makefile
> +++ b/drivers/clk/sunxi/Makefile
> @@ -15,6 +15,7 @@ obj-y += clk-sun9i-core.o
>  obj-y += clk-sun9i-mmc.o
>  obj-y += clk-usb.o
>  
> +obj-$(CONFIG_MACH_SUN9I) += clk-sun8i-apb0.o
> +

So sun8i doesn't use it?

>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
> -	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
> -	clk-sun8i-apb0.o
> +	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o
> diff --git a/drivers/clk/sunxi/clk-sun8i-apb0.c b/drivers/clk/sunxi/clk-sun8i-apb0.c
> index 7ae5d2c2cde1..c1e2ac8f4b0d 100644
> --- a/drivers/clk/sunxi/clk-sun8i-apb0.c
> +++ b/drivers/clk/sunxi/clk-sun8i-apb0.c
> @@ -17,13 +17,68 @@
>  #include <linux/clk-provider.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> +#include <linux/of_address.h>
>  #include <linux/platform_device.h>
>  
> +static struct clk *sun8i_a23_apb0_register(struct device_node *node,
> +					   void __iomem *reg)
> +{
> +	const char *clk_name = node->name;
> +	const char *clk_parent;
> +	struct clk *clk;
> +	int ret;
> +
> +	clk_parent = of_clk_get_parent_name(node, 0);
> +	if (!clk_parent)
> +		return ERR_PTR(-EINVAL);
> +
> +	of_property_read_string(node, "clock-output-names", &clk_name);
> +
> +	/* The A23 APB0 clock is a standard 2 bit wide divider clock */
> +	clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg,
> +				   0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
> +	if (IS_ERR(clk))
> +		return clk;
> +
> +	ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +	if (ret)
> +		goto err_unregister;
> +
> +	return clk;
> +
> +err_unregister:
> +	clk_unregister_divider(clk);
> +
> +	return ERR_PTR(ret);
> +}
> +
> +static void sun8i_a23_apb0_setup(struct device_node *node)
> +{
> +	void __iomem *reg;
> +	struct resource res;
> +	struct clk *clk;
> +
> +	reg = of_io_request_and_map(node, 0, of_node_full_name(node));
> +	if (IS_ERR(reg))
> +		return;
> +
> +	clk = sun8i_a23_apb0_register(node, reg);
> +	if (IS_ERR(clk))
> +		goto err_unmap;
> +
> +	return;
> +
> +err_unmap:
> +	iounmap(reg);
> +	of_address_to_resource(node, 0, &res);
> +	release_mem_region(res.start, resource_size(&res));
> +}
> +CLK_OF_DECLARE(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk",
> +	       sun8i_a23_apb0_setup);
> +
>  static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
>  {
>  	struct device_node *np = pdev->dev.of_node;
> -	const char *clk_name = np->name;
> -	const char *clk_parent;
>  	struct resource *r;
>  	void __iomem *reg;
>  	struct clk *clk;
> @@ -33,19 +88,11 @@ static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
>  	if (IS_ERR(reg))
>  		return PTR_ERR(reg);
>  
> -	clk_parent = of_clk_get_parent_name(np, 0);
> -	if (!clk_parent)
> -		return -EINVAL;
> -
> -	of_property_read_string(np, "clock-output-names", &clk_name);
> -
> -	/* The A23 APB0 clock is a standard 2 bit wide divider clock */
> -	clk = clk_register_divider(&pdev->dev, clk_name, clk_parent, 0, reg,
> -				   0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
> +	clk = sun8i_a23_apb0_register(np, reg);
>  	if (IS_ERR(clk))
>  		return PTR_ERR(clk);
>  
> -	return of_clk_add_provider(np, of_clk_src_simple_get, clk);
> +	return 0;
>  }

Won't this probe twice now? First the CLK_OF_DECLARE will register a
clock, and then the device model will call probe a second time.

I guess then request_mem_region will catch it, but then you return an
error code, which is probably an error success, since the clock is
registered :)

Maxime

Chen-Yu Tsai Dec. 1, 2015, 11:54 a.m. UTC | #2

On Tue, Dec 1, 2015 at 6:04 PM, Maxime Ripard
<[e-mail]> wrote:
> Hi,
>
> On Sun, Nov 29, 2015 at 11:03:06AM +0800, Chen-Yu Tsai wrote:
>> The APBS clock on sun9i is the same as the APB0 clock on sun8i. With
>> sun9i we are supporting the PRCM clocks by using CLK_OF_DECLARE,
>> instead of through a PRCM mfd device and subdevices for each clock
>> and reset control. As such we need a CLK_OF_DECLARE version of
>> the sun8i-a23-apb0-clk driver.
>>
>> Also, build it for sun9i/A80, and not just for configurations with
>> MFD_SUN6I_PRCM enabled.
>>
>> Signed-off-by: Chen-Yu Tsai <[e-mail]>
>> ---
>>  drivers/clk/sunxi/Makefile         |  5 +--
>>  drivers/clk/sunxi/clk-sun8i-apb0.c | 71 +++++++++++++++++++++++++++++++-------
>>  2 files changed, 62 insertions(+), 14 deletions(-)
>>
>> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
>> index cb4c299214ce..c55d5cd1c0e5 100644
>> --- a/drivers/clk/sunxi/Makefile
>> +++ b/drivers/clk/sunxi/Makefile
>> @@ -15,6 +15,7 @@ obj-y += clk-sun9i-core.o
>>  obj-y += clk-sun9i-mmc.o
>>  obj-y += clk-usb.o
>>
>> +obj-$(CONFIG_MACH_SUN9I) += clk-sun8i-apb0.o
>> +
>
> So sun8i doesn't use it?

Shit... I messed up. clk-sun8i-apb0.o should also be under
CONFIG_MFD_SUN6I_PRCM.

I'll send a new version of this patch. No need to keep spamming
people with the whole series.

>>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
>> -     clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
>> -     clk-sun8i-apb0.o
>> +     clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o
>> diff --git a/drivers/clk/sunxi/clk-sun8i-apb0.c b/drivers/clk/sunxi/clk-sun8i-apb0.c
>> index 7ae5d2c2cde1..c1e2ac8f4b0d 100644
>> --- a/drivers/clk/sunxi/clk-sun8i-apb0.c
>> +++ b/drivers/clk/sunxi/clk-sun8i-apb0.c
>> @@ -17,13 +17,68 @@
>>  #include <linux/clk-provider.h>
>>  #include <linux/module.h>
>>  #include <linux/of.h>
>> +#include <linux/of_address.h>
>>  #include <linux/platform_device.h>
>>
>> +static struct clk *sun8i_a23_apb0_register(struct device_node *node,
>> +                                        void __iomem *reg)
>> +{
>> +     const char *clk_name = node->name;
>> +     const char *clk_parent;
>> +     struct clk *clk;
>> +     int ret;
>> +
>> +     clk_parent = of_clk_get_parent_name(node, 0);
>> +     if (!clk_parent)
>> +             return ERR_PTR(-EINVAL);
>> +
>> +     of_property_read_string(node, "clock-output-names", &clk_name);
>> +
>> +     /* The A23 APB0 clock is a standard 2 bit wide divider clock */
>> +     clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg,
>> +                                0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
>> +     if (IS_ERR(clk))
>> +             return clk;
>> +
>> +     ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
>> +     if (ret)
>> +             goto err_unregister;
>> +
>> +     return clk;
>> +
>> +err_unregister:
>> +     clk_unregister_divider(clk);
>> +
>> +     return ERR_PTR(ret);
>> +}
>> +
>> +static void sun8i_a23_apb0_setup(struct device_node *node)
>> +{
>> +     void __iomem *reg;
>> +     struct resource res;
>> +     struct clk *clk;
>> +
>> +     reg = of_io_request_and_map(node, 0, of_node_full_name(node));
>> +     if (IS_ERR(reg))
>> +             return;
>> +
>> +     clk = sun8i_a23_apb0_register(node, reg);
>> +     if (IS_ERR(clk))
>> +             goto err_unmap;
>> +
>> +     return;
>> +
>> +err_unmap:
>> +     iounmap(reg);
>> +     of_address_to_resource(node, 0, &res);
>> +     release_mem_region(res.start, resource_size(&res));
>> +}
>> +CLK_OF_DECLARE(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk",
>> +            sun8i_a23_apb0_setup);
>> +
>>  static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
>>  {
>>       struct device_node *np = pdev->dev.of_node;
>> -     const char *clk_name = np->name;
>> -     const char *clk_parent;
>>       struct resource *r;
>>       void __iomem *reg;
>>       struct clk *clk;
>> @@ -33,19 +88,11 @@ static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
>>       if (IS_ERR(reg))
>>               return PTR_ERR(reg);
>>
>> -     clk_parent = of_clk_get_parent_name(np, 0);
>> -     if (!clk_parent)
>> -             return -EINVAL;
>> -
>> -     of_property_read_string(np, "clock-output-names", &clk_name);
>> -
>> -     /* The A23 APB0 clock is a standard 2 bit wide divider clock */
>> -     clk = clk_register_divider(&pdev->dev, clk_name, clk_parent, 0, reg,
>> -                                0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
>> +     clk = sun8i_a23_apb0_register(np, reg);
>>       if (IS_ERR(clk))
>>               return PTR_ERR(clk);
>>
>> -     return of_clk_add_provider(np, of_clk_src_simple_get, clk);
>> +     return 0;
>>  }
>
> Won't this probe twice now? First the CLK_OF_DECLARE will register a
> clock, and then the device model will call probe a second time.

AFAIK it will.

> I guess then request_mem_region will catch it, but then you return an
> error code, which is probably an error success, since the clock is
> registered :)

Indeed. clk-mod0.c actually has a comment block explaining this.
I didn't want to repeat the whole thing though.

Regards
ChenYu

Maxime Ripard Dec. 1, 2015, 12:50 p.m. UTC | #3

On Tue, Dec 01, 2015 at 07:54:06PM +0800, Chen-Yu Tsai wrote:
> On Tue, Dec 1, 2015 at 6:04 PM, Maxime Ripard
> <[e-mail]> wrote:
> > Hi,
> >
> > On Sun, Nov 29, 2015 at 11:03:06AM +0800, Chen-Yu Tsai wrote:
> >> The APBS clock on sun9i is the same as the APB0 clock on sun8i. With
> >> sun9i we are supporting the PRCM clocks by using CLK_OF_DECLARE,
> >> instead of through a PRCM mfd device and subdevices for each clock
> >> and reset control. As such we need a CLK_OF_DECLARE version of
> >> the sun8i-a23-apb0-clk driver.
> >>
> >> Also, build it for sun9i/A80, and not just for configurations with
> >> MFD_SUN6I_PRCM enabled.
> >>
> >> Signed-off-by: Chen-Yu Tsai <[e-mail]>
> >> ---
> >>  drivers/clk/sunxi/Makefile         |  5 +--
> >>  drivers/clk/sunxi/clk-sun8i-apb0.c | 71 +++++++++++++++++++++++++++++++-------
> >>  2 files changed, 62 insertions(+), 14 deletions(-)
> >>
> >> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> >> index cb4c299214ce..c55d5cd1c0e5 100644
> >> --- a/drivers/clk/sunxi/Makefile
> >> +++ b/drivers/clk/sunxi/Makefile
> >> @@ -15,6 +15,7 @@ obj-y += clk-sun9i-core.o
> >>  obj-y += clk-sun9i-mmc.o
> >>  obj-y += clk-usb.o
> >>
> >> +obj-$(CONFIG_MACH_SUN9I) += clk-sun8i-apb0.o
> >> +
> >
> > So sun8i doesn't use it?
> 
> Shit... I messed up. clk-sun8i-apb0.o should also be under
> CONFIG_MFD_SUN6I_PRCM.
> 
> I'll send a new version of this patch. No need to keep spamming
> people with the whole series.

Ok.

> >>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
> >> -     clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
> >> -     clk-sun8i-apb0.o
> >> +     clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o
> >> diff --git a/drivers/clk/sunxi/clk-sun8i-apb0.c b/drivers/clk/sunxi/clk-sun8i-apb0.c
> >> index 7ae5d2c2cde1..c1e2ac8f4b0d 100644
> >> --- a/drivers/clk/sunxi/clk-sun8i-apb0.c
> >> +++ b/drivers/clk/sunxi/clk-sun8i-apb0.c
> >> @@ -17,13 +17,68 @@
> >>  #include <linux/clk-provider.h>
> >>  #include <linux/module.h>
> >>  #include <linux/of.h>
> >> +#include <linux/of_address.h>
> >>  #include <linux/platform_device.h>
> >>
> >> +static struct clk *sun8i_a23_apb0_register(struct device_node *node,
> >> +                                        void __iomem *reg)
> >> +{
> >> +     const char *clk_name = node->name;
> >> +     const char *clk_parent;
> >> +     struct clk *clk;
> >> +     int ret;
> >> +
> >> +     clk_parent = of_clk_get_parent_name(node, 0);
> >> +     if (!clk_parent)
> >> +             return ERR_PTR(-EINVAL);
> >> +
> >> +     of_property_read_string(node, "clock-output-names", &clk_name);
> >> +
> >> +     /* The A23 APB0 clock is a standard 2 bit wide divider clock */
> >> +     clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg,
> >> +                                0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
> >> +     if (IS_ERR(clk))
> >> +             return clk;
> >> +
> >> +     ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
> >> +     if (ret)
> >> +             goto err_unregister;
> >> +
> >> +     return clk;
> >> +
> >> +err_unregister:
> >> +     clk_unregister_divider(clk);
> >> +
> >> +     return ERR_PTR(ret);
> >> +}
> >> +
> >> +static void sun8i_a23_apb0_setup(struct device_node *node)
> >> +{
> >> +     void __iomem *reg;
> >> +     struct resource res;
> >> +     struct clk *clk;
> >> +
> >> +     reg = of_io_request_and_map(node, 0, of_node_full_name(node));
> >> +     if (IS_ERR(reg))
> >> +             return;
> >> +
> >> +     clk = sun8i_a23_apb0_register(node, reg);
> >> +     if (IS_ERR(clk))
> >> +             goto err_unmap;
> >> +
> >> +     return;
> >> +
> >> +err_unmap:
> >> +     iounmap(reg);
> >> +     of_address_to_resource(node, 0, &res);
> >> +     release_mem_region(res.start, resource_size(&res));
> >> +}
> >> +CLK_OF_DECLARE(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk",
> >> +            sun8i_a23_apb0_setup);
> >> +
> >>  static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
> >>  {
> >>       struct device_node *np = pdev->dev.of_node;
> >> -     const char *clk_name = np->name;
> >> -     const char *clk_parent;
> >>       struct resource *r;
> >>       void __iomem *reg;
> >>       struct clk *clk;
> >> @@ -33,19 +88,11 @@ static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
> >>       if (IS_ERR(reg))
> >>               return PTR_ERR(reg);
> >>
> >> -     clk_parent = of_clk_get_parent_name(np, 0);
> >> -     if (!clk_parent)
> >> -             return -EINVAL;
> >> -
> >> -     of_property_read_string(np, "clock-output-names", &clk_name);
> >> -
> >> -     /* The A23 APB0 clock is a standard 2 bit wide divider clock */
> >> -     clk = clk_register_divider(&pdev->dev, clk_name, clk_parent, 0, reg,
> >> -                                0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
> >> +     clk = sun8i_a23_apb0_register(np, reg);
> >>       if (IS_ERR(clk))
> >>               return PTR_ERR(clk);
> >>
> >> -     return of_clk_add_provider(np, of_clk_src_simple_get, clk);
> >> +     return 0;
> >>  }
> >
> > Won't this probe twice now? First the CLK_OF_DECLARE will register a
> > clock, and then the device model will call probe a second time.
> 
> AFAIK it will.
> 
> > I guess then request_mem_region will catch it, but then you return an
> > error code, which is probably an error success, since the clock is
> > registered :)
> 
> Indeed. clk-mod0.c actually has a comment block explaining this.
> I didn't want to repeat the whole thing though.

I guess, we can simply return 0 if of_io_request_and_map returns
EBUSY, since it would simply mean that we already probed.

Maxime

Chen-Yu Tsai Dec. 1, 2015, 2:19 p.m. UTC | #4

On Tue, Dec 1, 2015 at 8:50 PM, Maxime Ripard
<[e-mail]> wrote:
> On Tue, Dec 01, 2015 at 07:54:06PM +0800, Chen-Yu Tsai wrote:
>> On Tue, Dec 1, 2015 at 6:04 PM, Maxime Ripard
>> <[e-mail]> wrote:
>> > Hi,
>> >
>> > On Sun, Nov 29, 2015 at 11:03:06AM +0800, Chen-Yu Tsai wrote:
>> >> The APBS clock on sun9i is the same as the APB0 clock on sun8i. With
>> >> sun9i we are supporting the PRCM clocks by using CLK_OF_DECLARE,
>> >> instead of through a PRCM mfd device and subdevices for each clock
>> >> and reset control. As such we need a CLK_OF_DECLARE version of
>> >> the sun8i-a23-apb0-clk driver.
>> >>
>> >> Also, build it for sun9i/A80, and not just for configurations with
>> >> MFD_SUN6I_PRCM enabled.
>> >>
>> >> Signed-off-by: Chen-Yu Tsai <[e-mail]>
>> >> ---
>> >>  drivers/clk/sunxi/Makefile         |  5 +--
>> >>  drivers/clk/sunxi/clk-sun8i-apb0.c | 71 +++++++++++++++++++++++++++++++-------
>> >>  2 files changed, 62 insertions(+), 14 deletions(-)
>> >>
>> >> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
>> >> index cb4c299214ce..c55d5cd1c0e5 100644
>> >> --- a/drivers/clk/sunxi/Makefile
>> >> +++ b/drivers/clk/sunxi/Makefile
>> >> @@ -15,6 +15,7 @@ obj-y += clk-sun9i-core.o
>> >>  obj-y += clk-sun9i-mmc.o
>> >>  obj-y += clk-usb.o
>> >>
>> >> +obj-$(CONFIG_MACH_SUN9I) += clk-sun8i-apb0.o
>> >> +
>> >
>> > So sun8i doesn't use it?
>>
>> Shit... I messed up. clk-sun8i-apb0.o should also be under
>> CONFIG_MFD_SUN6I_PRCM.
>>
>> I'll send a new version of this patch. No need to keep spamming
>> people with the whole series.
>
> Ok.
>
>> >>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
>> >> -     clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
>> >> -     clk-sun8i-apb0.o
>> >> +     clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o
>> >> diff --git a/drivers/clk/sunxi/clk-sun8i-apb0.c b/drivers/clk/sunxi/clk-sun8i-apb0.c
>> >> index 7ae5d2c2cde1..c1e2ac8f4b0d 100644
>> >> --- a/drivers/clk/sunxi/clk-sun8i-apb0.c
>> >> +++ b/drivers/clk/sunxi/clk-sun8i-apb0.c
>> >> @@ -17,13 +17,68 @@
>> >>  #include <linux/clk-provider.h>
>> >>  #include <linux/module.h>
>> >>  #include <linux/of.h>
>> >> +#include <linux/of_address.h>
>> >>  #include <linux/platform_device.h>
>> >>
>> >> +static struct clk *sun8i_a23_apb0_register(struct device_node *node,
>> >> +                                        void __iomem *reg)
>> >> +{
>> >> +     const char *clk_name = node->name;
>> >> +     const char *clk_parent;
>> >> +     struct clk *clk;
>> >> +     int ret;
>> >> +
>> >> +     clk_parent = of_clk_get_parent_name(node, 0);
>> >> +     if (!clk_parent)
>> >> +             return ERR_PTR(-EINVAL);
>> >> +
>> >> +     of_property_read_string(node, "clock-output-names", &clk_name);
>> >> +
>> >> +     /* The A23 APB0 clock is a standard 2 bit wide divider clock */
>> >> +     clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg,
>> >> +                                0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
>> >> +     if (IS_ERR(clk))
>> >> +             return clk;
>> >> +
>> >> +     ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
>> >> +     if (ret)
>> >> +             goto err_unregister;
>> >> +
>> >> +     return clk;
>> >> +
>> >> +err_unregister:
>> >> +     clk_unregister_divider(clk);
>> >> +
>> >> +     return ERR_PTR(ret);
>> >> +}
>> >> +
>> >> +static void sun8i_a23_apb0_setup(struct device_node *node)
>> >> +{
>> >> +     void __iomem *reg;
>> >> +     struct resource res;
>> >> +     struct clk *clk;
>> >> +
>> >> +     reg = of_io_request_and_map(node, 0, of_node_full_name(node));
>> >> +     if (IS_ERR(reg))
>> >> +             return;
>> >> +
>> >> +     clk = sun8i_a23_apb0_register(node, reg);
>> >> +     if (IS_ERR(clk))
>> >> +             goto err_unmap;
>> >> +
>> >> +     return;
>> >> +
>> >> +err_unmap:
>> >> +     iounmap(reg);
>> >> +     of_address_to_resource(node, 0, &res);
>> >> +     release_mem_region(res.start, resource_size(&res));
>> >> +}
>> >> +CLK_OF_DECLARE(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk",
>> >> +            sun8i_a23_apb0_setup);
>> >> +
>> >>  static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
>> >>  {
>> >>       struct device_node *np = pdev->dev.of_node;
>> >> -     const char *clk_name = np->name;
>> >> -     const char *clk_parent;
>> >>       struct resource *r;
>> >>       void __iomem *reg;
>> >>       struct clk *clk;
>> >> @@ -33,19 +88,11 @@ static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
>> >>       if (IS_ERR(reg))
>> >>               return PTR_ERR(reg);
>> >>
>> >> -     clk_parent = of_clk_get_parent_name(np, 0);
>> >> -     if (!clk_parent)
>> >> -             return -EINVAL;
>> >> -
>> >> -     of_property_read_string(np, "clock-output-names", &clk_name);
>> >> -
>> >> -     /* The A23 APB0 clock is a standard 2 bit wide divider clock */
>> >> -     clk = clk_register_divider(&pdev->dev, clk_name, clk_parent, 0, reg,
>> >> -                                0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
>> >> +     clk = sun8i_a23_apb0_register(np, reg);
>> >>       if (IS_ERR(clk))
>> >>               return PTR_ERR(clk);
>> >>
>> >> -     return of_clk_add_provider(np, of_clk_src_simple_get, clk);
>> >> +     return 0;
>> >>  }
>> >
>> > Won't this probe twice now? First the CLK_OF_DECLARE will register a
>> > clock, and then the device model will call probe a second time.
>>
>> AFAIK it will.
>>
>> > I guess then request_mem_region will catch it, but then you return an
>> > error code, which is probably an error success, since the clock is
>> > registered :)
>>
>> Indeed. clk-mod0.c actually has a comment block explaining this.
>> I didn't want to repeat the whole thing though.
>
> I guess, we can simply return 0 if of_io_request_and_map returns
> EBUSY, since it would simply mean that we already probed.

I think CLK_OF_DECLARE gets probed first, then platform devices.
of_io_request_and_map fails for mfd cells, which have no DT reg
properties. So we should be ignoring -EINVAL instead of -EBUSY.
But yeah, I'll have it return 0 in this case, and add a brief
comment.

ChenYu

Chen-Yu Tsai Dec. 1, 2015, 2:39 p.m. UTC | #5

On Tue, Dec 1, 2015 at 10:19 PM, Chen-Yu Tsai <[e-mail]> wrote:
> On Tue, Dec 1, 2015 at 8:50 PM, Maxime Ripard
> <[e-mail]> wrote:
>> On Tue, Dec 01, 2015 at 07:54:06PM +0800, Chen-Yu Tsai wrote:
>>> On Tue, Dec 1, 2015 at 6:04 PM, Maxime Ripard
>>> <[e-mail]> wrote:
>>> > Hi,
>>> >
>>> > On Sun, Nov 29, 2015 at 11:03:06AM +0800, Chen-Yu Tsai wrote:
>>> >> The APBS clock on sun9i is the same as the APB0 clock on sun8i. With
>>> >> sun9i we are supporting the PRCM clocks by using CLK_OF_DECLARE,
>>> >> instead of through a PRCM mfd device and subdevices for each clock
>>> >> and reset control. As such we need a CLK_OF_DECLARE version of
>>> >> the sun8i-a23-apb0-clk driver.
>>> >>
>>> >> Also, build it for sun9i/A80, and not just for configurations with
>>> >> MFD_SUN6I_PRCM enabled.
>>> >>
>>> >> Signed-off-by: Chen-Yu Tsai <[e-mail]>
>>> >> ---
>>> >>  drivers/clk/sunxi/Makefile         |  5 +--
>>> >>  drivers/clk/sunxi/clk-sun8i-apb0.c | 71 +++++++++++++++++++++++++++++++-------
>>> >>  2 files changed, 62 insertions(+), 14 deletions(-)
>>> >>
>>> >> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
>>> >> index cb4c299214ce..c55d5cd1c0e5 100644
>>> >> --- a/drivers/clk/sunxi/Makefile
>>> >> +++ b/drivers/clk/sunxi/Makefile
>>> >> @@ -15,6 +15,7 @@ obj-y += clk-sun9i-core.o
>>> >>  obj-y += clk-sun9i-mmc.o
>>> >>  obj-y += clk-usb.o
>>> >>
>>> >> +obj-$(CONFIG_MACH_SUN9I) += clk-sun8i-apb0.o
>>> >> +
>>> >
>>> > So sun8i doesn't use it?
>>>
>>> Shit... I messed up. clk-sun8i-apb0.o should also be under
>>> CONFIG_MFD_SUN6I_PRCM.
>>>
>>> I'll send a new version of this patch. No need to keep spamming
>>> people with the whole series.
>>
>> Ok.
>>
>>> >>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
>>> >> -     clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
>>> >> -     clk-sun8i-apb0.o
>>> >> +     clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o
>>> >> diff --git a/drivers/clk/sunxi/clk-sun8i-apb0.c b/drivers/clk/sunxi/clk-sun8i-apb0.c
>>> >> index 7ae5d2c2cde1..c1e2ac8f4b0d 100644
>>> >> --- a/drivers/clk/sunxi/clk-sun8i-apb0.c
>>> >> +++ b/drivers/clk/sunxi/clk-sun8i-apb0.c
>>> >> @@ -17,13 +17,68 @@
>>> >>  #include <linux/clk-provider.h>
>>> >>  #include <linux/module.h>
>>> >>  #include <linux/of.h>
>>> >> +#include <linux/of_address.h>
>>> >>  #include <linux/platform_device.h>
>>> >>
>>> >> +static struct clk *sun8i_a23_apb0_register(struct device_node *node,
>>> >> +                                        void __iomem *reg)
>>> >> +{
>>> >> +     const char *clk_name = node->name;
>>> >> +     const char *clk_parent;
>>> >> +     struct clk *clk;
>>> >> +     int ret;
>>> >> +
>>> >> +     clk_parent = of_clk_get_parent_name(node, 0);
>>> >> +     if (!clk_parent)
>>> >> +             return ERR_PTR(-EINVAL);
>>> >> +
>>> >> +     of_property_read_string(node, "clock-output-names", &clk_name);
>>> >> +
>>> >> +     /* The A23 APB0 clock is a standard 2 bit wide divider clock */
>>> >> +     clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg,
>>> >> +                                0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
>>> >> +     if (IS_ERR(clk))
>>> >> +             return clk;
>>> >> +
>>> >> +     ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
>>> >> +     if (ret)
>>> >> +             goto err_unregister;
>>> >> +
>>> >> +     return clk;
>>> >> +
>>> >> +err_unregister:
>>> >> +     clk_unregister_divider(clk);
>>> >> +
>>> >> +     return ERR_PTR(ret);
>>> >> +}
>>> >> +
>>> >> +static void sun8i_a23_apb0_setup(struct device_node *node)
>>> >> +{
>>> >> +     void __iomem *reg;
>>> >> +     struct resource res;
>>> >> +     struct clk *clk;
>>> >> +
>>> >> +     reg = of_io_request_and_map(node, 0, of_node_full_name(node));
>>> >> +     if (IS_ERR(reg))
>>> >> +             return;
>>> >> +
>>> >> +     clk = sun8i_a23_apb0_register(node, reg);
>>> >> +     if (IS_ERR(clk))
>>> >> +             goto err_unmap;
>>> >> +
>>> >> +     return;
>>> >> +
>>> >> +err_unmap:
>>> >> +     iounmap(reg);
>>> >> +     of_address_to_resource(node, 0, &res);
>>> >> +     release_mem_region(res.start, resource_size(&res));
>>> >> +}
>>> >> +CLK_OF_DECLARE(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk",
>>> >> +            sun8i_a23_apb0_setup);
>>> >> +
>>> >>  static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
>>> >>  {
>>> >>       struct device_node *np = pdev->dev.of_node;
>>> >> -     const char *clk_name = np->name;
>>> >> -     const char *clk_parent;
>>> >>       struct resource *r;
>>> >>       void __iomem *reg;
>>> >>       struct clk *clk;
>>> >> @@ -33,19 +88,11 @@ static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
>>> >>       if (IS_ERR(reg))
>>> >>               return PTR_ERR(reg);
>>> >>
>>> >> -     clk_parent = of_clk_get_parent_name(np, 0);
>>> >> -     if (!clk_parent)
>>> >> -             return -EINVAL;
>>> >> -
>>> >> -     of_property_read_string(np, "clock-output-names", &clk_name);
>>> >> -
>>> >> -     /* The A23 APB0 clock is a standard 2 bit wide divider clock */
>>> >> -     clk = clk_register_divider(&pdev->dev, clk_name, clk_parent, 0, reg,
>>> >> -                                0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
>>> >> +     clk = sun8i_a23_apb0_register(np, reg);
>>> >>       if (IS_ERR(clk))
>>> >>               return PTR_ERR(clk);
>>> >>
>>> >> -     return of_clk_add_provider(np, of_clk_src_simple_get, clk);
>>> >> +     return 0;
>>> >>  }
>>> >
>>> > Won't this probe twice now? First the CLK_OF_DECLARE will register a
>>> > clock, and then the device model will call probe a second time.
>>>
>>> AFAIK it will.
>>>
>>> > I guess then request_mem_region will catch it, but then you return an
>>> > error code, which is probably an error success, since the clock is
>>> > registered :)
>>>
>>> Indeed. clk-mod0.c actually has a comment block explaining this.
>>> I didn't want to repeat the whole thing though.
>>
>> I guess, we can simply return 0 if of_io_request_and_map returns
>> EBUSY, since it would simply mean that we already probed.
>
> I think CLK_OF_DECLARE gets probed first, then platform devices.
> of_io_request_and_map fails for mfd cells, which have no DT reg
> properties. So we should be ignoring -EINVAL instead of -EBUSY.

Right... I misread your comment. You're talking about the platform device
part. About ignoring the error here: normally we use CLK_OF_DECLARE with
clocks under the "clocks" node, which don't get registered as platform
device. (Or is this not so common?) So if one does get probed twice, I
think we shouldn't ignore the error. It's likely the DT has a problem
and the probe error will let the user know.

What do you think?

ChenYu

> But yeah, I'll have it return 0 in this case, and add a brief
> comment.

Patch

diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
index cb4c299214ce..c55d5cd1c0e5 100644
--- a/drivers/clk/sunxi/Makefile
+++ b/drivers/clk/sunxi/Makefile
@@ -15,6 +15,7 @@  obj-y += clk-sun9i-core.o
 obj-y += clk-sun9i-mmc.o
 obj-y += clk-usb.o
 
+obj-$(CONFIG_MACH_SUN9I) += clk-sun8i-apb0.o
+
 obj-$(CONFIG_MFD_SUN6I_PRCM) += \
-	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
-	clk-sun8i-apb0.o
+	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o
diff --git a/drivers/clk/sunxi/clk-sun8i-apb0.c b/drivers/clk/sunxi/clk-sun8i-apb0.c
index 7ae5d2c2cde1..c1e2ac8f4b0d 100644
--- a/drivers/clk/sunxi/clk-sun8i-apb0.c
+++ b/drivers/clk/sunxi/clk-sun8i-apb0.c
@@ -17,13 +17,68 @@ 
 #include <linux/clk-provider.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/platform_device.h>
 
+static struct clk *sun8i_a23_apb0_register(struct device_node *node,
+					   void __iomem *reg)
+{
+	const char *clk_name = node->name;
+	const char *clk_parent;
+	struct clk *clk;
+	int ret;
+
+	clk_parent = of_clk_get_parent_name(node, 0);
+	if (!clk_parent)
+		return ERR_PTR(-EINVAL);
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+
+	/* The A23 APB0 clock is a standard 2 bit wide divider clock */
+	clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg,
+				   0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
+	if (IS_ERR(clk))
+		return clk;
+
+	ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
+	if (ret)
+		goto err_unregister;
+
+	return clk;
+
+err_unregister:
+	clk_unregister_divider(clk);
+
+	return ERR_PTR(ret);
+}
+
+static void sun8i_a23_apb0_setup(struct device_node *node)
+{
+	void __iomem *reg;
+	struct resource res;
+	struct clk *clk;
+
+	reg = of_io_request_and_map(node, 0, of_node_full_name(node));
+	if (IS_ERR(reg))
+		return;
+
+	clk = sun8i_a23_apb0_register(node, reg);
+	if (IS_ERR(clk))
+		goto err_unmap;
+
+	return;
+
+err_unmap:
+	iounmap(reg);
+	of_address_to_resource(node, 0, &res);
+	release_mem_region(res.start, resource_size(&res));
+}
+CLK_OF_DECLARE(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk",
+	       sun8i_a23_apb0_setup);
+
 static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
-	const char *clk_name = np->name;
-	const char *clk_parent;
 	struct resource *r;
 	void __iomem *reg;
 	struct clk *clk;
@@ -33,19 +88,11 @@  static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
 	if (IS_ERR(reg))
 		return PTR_ERR(reg);
 
-	clk_parent = of_clk_get_parent_name(np, 0);
-	if (!clk_parent)
-		return -EINVAL;
-
-	of_property_read_string(np, "clock-output-names", &clk_name);
-
-	/* The A23 APB0 clock is a standard 2 bit wide divider clock */
-	clk = clk_register_divider(&pdev->dev, clk_name, clk_parent, 0, reg,
-				   0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
+	clk = sun8i_a23_apb0_register(np, reg);
 	if (IS_ERR(clk))
 		return PTR_ERR(clk);
 
-	return of_clk_add_provider(np, of_clk_src_simple_get, clk);
+	return 0;
 }
 
 static const struct of_device_id sun8i_a23_apb0_clk_dt_ids[] = {